KR100438183B1 - Method for over load in high data communication system - Google Patents

Abstract

The present invention relates to controlling a data transmission call of a terminal according to an allowance rate of a processor determined for overload control in a high speed data communication system. The overload control method in a high speed data communication system according to the present invention includes: Checking whether the measured share of the processor is greater than or equal to the reference load for each control period for changing the control level according to the share occupancy measurement period of the processor; Recognizing an initial overload level and reporting an overload occurrence to a processor and a module in the base station when the processor occupancy is equal to or greater than the reference load and continues for a time set as the processor occupancy target value; And limiting the data originating call by transmitting an access parameter in the base station to the terminal.

Description

Overload control method in high speed data communication system {Method for over load in high data communication system}

In the high-speed data communication system, in particular, the high-speed data service dedicated system (e.g., 1xEV-DO) is overloaded to overload a data transmission call between an access terminal (AT) and an access network (AN). In order to control, the present invention relates to an overload control method for differentially controlling a data call attempt from a terminal in order to control an overload of a service requiring continuous connection establishment when a session is not connected.

1x Ev-DO (Evolution Data Only), a system dedicated to high-speed data service, is a dedicated protocol for packet data transmission that is completely different from the existing IS-2000 wireless protocol, and can transmit up to 2.457Mbps when the maximum data rate is forward.

Qualcomm's success in commercializing cdmaOne and cdma2000 technologies has resulted in the development of 1xEV (formerly known as HDR (High Data Rate)), which was developed by the CDG (CDMA Development Group) to address HDR as 1xEV to cope with asynchronous IMT-2000. System.

Since the service that the terminal downloads from the system (for example, the Internet) is dominant due to the characteristics of the packet data, the 1x EV-DO has a structure in which the forward and reverse channel rates are different. The forward has asymmetric data rate structure up to 2.457Mbps and the reverse up to 153.6kbps.

As shown in FIG. 1, the 1x Ev-DO system includes a terminal (AT) 101, an access network (AN) 102, a packet controller (PCF), a packet control node (PDSN), and a packet serving node (PDSN). Node 104) and an authentication server (AN-AAA). Here, the access network 102 is a general term for a base station and a control station of an existing 2G system, and the interface between the wireless terminal between the terminal 101 and the access network 102 conforms to C.S0024 (version 3.0) standard of 3GPP2.

The packet serving node (PDSN) 104 serves as a matching function for providing packet data services (eg, Internet access services) to the terminal. The authentication server (AN-AAA; Access Network- Authentication, Authorization, Accounting) functions as a 1xEV-DO subscriber authentication, is matched with the packet controller 103, and the interface conforms to the TIA / EIA / IS-878 standard.

2 is a diagram illustrating a general 1x EV-DO forward channel type.

Referring to FIG. 2, the forward channel structure from the access network (AN) to the terminal (AT) includes a pilot channel, a reverse activity channel, a reverse power control channel, a traffic channel, and a control ( Control) channel.

The pilot channel is used as a basic signal for system acquisition, and the traffic channel and control channel are used for transmitting data to be transmitted and control information for call processing control. MAC (Medium Access Control) channel is mainly used for transmission speed control and consists of Reverse Activity Channel, DRC Lock Channel, and Reverse Power Control Channel.

The reverse activity channel informs the terminal of congestion of the reverse traffic channel according to the amount of reverse traffic. The reverse power control channel controls the outgoing power of the reverse link of the terminal. The DRC lock channel tells the terminal whether or not the access network should decode the DRC coming from the terminal. In the forward direction, all physical channels are transmitted in one channel, which is transmitted in a time division multiplexing (TDM) manner.

Since the 1xEV-DO system is a data processing dedicated system, call processing flow is set differently as shown in FIGS. 3 and 4 according to whether session information for packet data exists in the packet controller database (PCF DB).

In general, the commercial terminal is automatically set up to the session establishment (Session Establishment), as shown in Figure 3 when the power off state from the power off (Power On) state.

First, a case of establishing a new session will be described with reference to FIG. 3.

The terminal transmits an UATI request message to the access network (ANTS / ANC) to request allocation of a unicast access terminal identifier (UATI) (S101), and the access network (AN) allocates a UATI to assign an UATI. ) Transmits the message to the terminal (S102).

Then, the terminal sends a UATI complete message to the access network (AN) to inform that it has received the UATI assignment message (S103), and in the subsequent establishment of the connection (Establishment) procedure, the terminal communicates with the access network (AN) In order to request the allocation of the forward traffic channel, the reverse power control channel, the reverse traffic channel required for the assignment (S104).

Thereafter, if there is no preset session between the terminal and the access network (AN), a procedure for establishing a session is performed (S105). The terminal transmits a message (XonRequest) for requesting a transition to the Open State (Access Stream) (S106), and the access network (AN) transmits a message (XonResponse) in response to the message (XonRequest) (S107).

After all of the session setup procedures are completed, the terminal performs a Point-to-Point Protocol (PPP) and a Link Control Protocol (LCP) procedure to perform the authentication procedure (S108).

The access network (AN) generates a Challenge Handshake Authentication Protocol (CHAP) Challenge packet defined in RFC 1994 and transmits it to the terminal (S109), and the access network (AN) receives a CHAP response packet from the terminal, and then authenticates. The RADIUS access request message is transmitted to the server AN AAA (S110). The authentication server (AN-AAA) transmits an access-accept message when authentication is successful after performing an authentication procedure (S111). Here, the access accept message includes an MN ID of 15 digits.

The access network (AN) notifies the terminal of the successful CHAP authentication (S112), and the terminal transmits a request message (XonRequest) for requesting a transition to an open state (service stream) to the access network (S113). The access network (AN) transmits a response message (XonResponse) to the terminal in response to the message (XonRequest) (S114).

At this time, the access network (AN) transmits A9-Setup-A8 to the packet controller for setting up the A8 connection and drives the timer T _A8-Setup (S115). Upon receiving the A9-Setup-A8 message, the packet controller performs an A10 / A11 connection establishment procedure and an A8 connection establishment with the packet serving node (S116).

Then, the access network AN receives the A9-Connect-A8 message from the packet controller and cancels the timer T _{A8 -Setup} driven in step 115 (S117). After the A10 / A11 connection setup is completed, the terminal and the packet serving node perform a PPP establishment procedure (S118), and transmit / receive packet data between the terminal and the packet serving node (S119).

4 illustrates a case of using an existing session (reactivation in a Dormant state).

Referring to FIG. 4, in the connection setup procedure, the terminal requests and receives a forward traffic channel, a reverse power control channel, and a reverse traffic channel for communication with the access network (AN) (S121).

Then, the access network (AN) transmits A9-Setup-A8 to the packet controller for establishing the A8 connection and drives the timer T _A8-Setup (S122), and the access network (AN) receives the A9-Connect-A8 message. And cancels the driven timer T _A8 -Setup. Thereafter, the terminal and the packet serving node transmit / receive data with each other (S124).

However, when the processor is overloaded in the conventional access network system, a method of controlling the overload by rejecting an outgoing message of a newly attempted call from the terminal is used. For example, in FIG. 3, this is a connection request message in the connection establishment. However, when the message control method is applied to the 1xEV-DO system, which is a data-only system, a session must be connected in order to transmit traffic data due to the data processing characteristics. The message is continuously sent to the processor of the access network, which causes a problem of increasing the load on the processor.

The present invention checks the load state of the processor of the access network, the data call control is performed according to the overload control level in case of overload, and high-speed data communication to provide a differential service according to the system protection and the degree of overload even in case of overload The purpose is to provide an overload control method in the system.

Another object of the present invention is to determine that the processor occupancy measured in each control interval is overload if the predetermined time duration exceeds the allowable limit, and to release the overload when the overload control level determined for each control interval is the minimum level and lasts for a predetermined time. An object of the present invention is to provide an overload control method in a high speed data communication system.

Still another object of the present invention is to provide a 0-12 grade for outgoing data control and a call control to a higher processor among control levels for calls input to the system in order to maintain processor occupancy at a target level in case of overload. The purpose of the present invention is to provide an overload control method in a high speed data communication system, characterized in that the overload processors are classified into 13 to 24 grades.

Another object of the present invention is to provide an overload control method in a high speed data communication system for controlling a data origination call from a terminal by using an access parameter allowable field value at an allowance rate determined according to an overload control level when data is overloaded. The purpose is.

1 is a configuration diagram of a high speed data communication system.

2 is a forward channel configuration diagram of a high speed data communication system.

3 is a flowchart illustrating an outgoing call setup procedure of a conventional high speed data communication system.

4 is a flowchart illustrating an outgoing call setup procedure when a conventional session exists.

5 is a table illustrating an overload control level in the overload control method in a high speed data communication system according to an exemplary embodiment of the present invention.

6 is a table illustrating a message structure of an access parameter of a high speed data communication system, according to an embodiment of the present invention.

7 is a flowchart illustrating a method for controlling overload in a high speed data communication system according to an exemplary embodiment of the present invention.

8 is a flowchart illustrating a data call control based on an allowance of an overload control level according to an exemplary embodiment of the present invention.

9 is a table showing field values in an access parameter message according to an overload control level tolerance rate according to an embodiment of the present invention.

An overload control method in a high speed data communication system according to the present invention for achieving the above object,

Checking whether the occupancy of the processor measured for each control period for changing the control level according to the occupancy measurement period of the processor is equal to or greater than the reference load;

Recognizing an initial overload level and reporting an overload occurrence to a processor and a module in the base station when the processor occupancy is equal to or greater than the reference load and continues for a time set as the processor occupancy target value;

Limiting the data originating call by transmitting an access parameter in the base station to the terminal.

Preferably, if the occupancy rate of the processor measured for each control period for changing the control level is less than the reference load, reducing the call control processor level by one level; Confirming that the level of the reduced call control processor is at a minimum level; If the check result is the minimum level, the overload release count value is increased, and the overload release step corresponds to a target count value.

Preferably, the control level is divided into 0 to 12 overload control class for controlling outgoing data of the lower processor and 13 to 24 overload control class requiring incoming call control to the upper processor, for interworking between the overload processors. It is done.

Preferably, the lower processor is a base station processor for outgoing call control, the upper processor is a call control processor in the base station controller for incoming call control, and the reference load, reference level, which is determined as the initial overload according to the situation of the processor, It is characterized in that the allowance of each determined overload control level can be arbitrarily changed.

Preferably, the overload control level corresponding to each of the control periods increases the overload control level if the measured load is greater than the initially set reference load in each cycle for measuring the occupancy of the processor. It is characterized in that the current level is maintained when the reference load is within the allowable value.

Preferably, the reference load, which is a comparison target of the load measured in the control section, includes a margin ratio for the target processor occupancy value, so that the overload control level is not changed frequently in each control section.

Preferably, the base station processor and the call control processor have a database for measuring and storing the measured processor load, and update the overload detection flag database and the overload level database for each measurement period, and perform call control with reference thereto. Characterized in that.

Preferably, when the base station is informed of the occurrence of the overload, determining the transmission allowance rate by the overload control level in the base station processor, and then determining the allowance value in the access parameter; And transmitting the allowance value in the determined access parameter to the terminal using a control message, and then controlling the originating call by the likelihood of acceptability in the allowance test at the terminal.

An overload control method in a high speed data communication system according to the present invention as described above will be described with reference to the accompanying drawings.

An access network (AN) represents a base station (BTS) and a base station controller (BSC) service system, each having a main processor called a base station processor (BSP) and a call control processor (CCP). By checking the load status of the processor, the data call control is performed by the overload control algorithm in case of overload, the system can be protected even in case of overload, and the differential service can be provided according to the degree of overload.

First, the overload detection and release method will be described.

The detection of the overload condition is determined as an overload when the processor occupied (ρ) measured every set control period (for example, 2 seconds) lasts more than 70% for 8 seconds (measured four times in two second cycles). The base control level of the overload is set to 12. The overload release ends the overload condition when the overload control level 0 level determined for each control section lasts for 10 seconds.

The overload control algorithm for this is as follows.

For processor overload control, only the CPU occupancy rate is used. Before explaining this, the terms used are explained as follows.

(A) Control level (L)

In order to maintain the processor occupancy at the target level during overload, calls input to the system are controlled by the overload control level L as shown in FIG. 5. The control level is basically divided into 0 to 12 grades for outgoing data control and 13 to 24 grades requiring incoming call control to a higher processor. This classification is for interworking between overloaded processors when two or more processors are configured.

In FIG. 5, when the overload control level is L <13 (BASE LEVEL), the outgoing call is controlled by the overload algorithm of the lowest-level processor (BSP) of the system, and in the case of L≥13, the lower-end processor (BSP) The outgoing call corresponding to level 13 is controlled by an outgoing call control algorithm, and in the case of a call control processor (CCP), the incoming call corresponding to level 13 is controlled. The base load and base level (BASE LOAD and BASE LEVEL) to judge the initial overload, and the allowance rate set for each overload control level can be modified by the operator, and the object to be rejected of the originating signal can be changed according to the situation.

(B) Control section

The control section refers to a section in which the control level (L) is changed according to a two-second period in which processor occupancy is measured. The control section determines the allowance rate of the call according to the control level for each control section and allows access in the access parameter (Access Parameter Persistenc: APersistence). Use the value to limit the call from the terminal.

The method of determining the overload control class for each control section is as follows. If the load measured in the control section (2 seconds) is larger than the initially set allowable value (BASE LOAD ± α), increase the rating and set the basic load allowance. If it is within (BASE LOAD ± α), the current rating is maintained, otherwise the rating is lowered.

Where m is the highest control level that actually controls and m = 24. α is a margin to 70% of the target value ρ * of the occupancy rate, and is set so that the overload control level does not fluctuate frequently for each control section.

(C) Data call control method

Access parameter that is sent down to the terminal through the control channel periodically (256 Chips = 256 * 1.666ms = 426.7ms) as specified in the specification in the 1xEV-DO system by using the allowance according to the overload level of the processor when overloaded. Use the Persistence Field value of. FIG. 6 is a diagram illustrating a message structure for an access parameter defined in 3GPP2 C.S0024 Ver.3.0 (version up standard for IS-856).

The purpose of the AP field value defined in the standard is an Access Persistence Vector. When the value in the vector is 0x3F, the acceptance probability (used in the Persistence Test) of the terminal is used. persistence, p) is set to 0 so that all calls attempted at the terminal are rejected and the base station cannot be accessed. If the value is not 0x3F, if the vector value of the access parameter allowance is n, the terminal is 2; ^The allow probability p is calculated as ^{-n / 4} to determine whether to allow the access to the base station. If the allowable probability (p) is not zero, the allowable probability (p) is generated by generating a uniformly distributed random number (x ) having a value of tolerance p and having a range of 0 < x <1. Perform a persistence test to compare the values. If x < p, the acceptance test succeeds and tries the call; if x≥p, the acceptance test fails and retries every access channel cycle (256 Chips = 256 * 1.666 ms = 426.7 ms). If p is 1, the success test for all origins is processed successfully and the access network is accessed in all cases.

FIG. 9 illustrates a correlation between an overload control level during overload and an access parameter allowance field value in an access parameter according to the present invention.

7 is a flowchart illustrating a method for detecting and releasing overload control according to the present invention.

Referring to FIG. 7, the control processor CCP or BSP measures the CPU load in units of a predetermined time (for example, 2 seconds) (S201) and stores the load in the load value database DB. There are ten load value storing databases DB, which are used for detecting and releasing the overload. After storage, the control processor (CCP and BSP) performs an overload detection process. When the load value has maintained the processor occupancy target value for a predetermined time (8 seconds or more), the overload detection flag database Flag DB and the overload level database DB are updated.

In this case, when the level at which the overload is checked is increased is compared with the reference load base_load (S202), when the level is greater than the reference load, the overload check count value is increased (S203). That is, the level at the first overload occurrence is a base level (base_level) defined by a user or a default value. Thereafter, if the load value is greater than the target processor occupancy value, that is, the reference load (base_load, in which the margin is about 2%), the level is increased by one step (S203), and when the load value is less than that, the level is decreased by one step (S207).

The control processor (CCP and BSP) call processing then enters the call restriction with reference to the overload detection database DB and the overload level database DB.

To this end, if the overload rise in each cycle is greater than or equal to the reference load, the check count value is increased every cycle, and if the predetermined count value is greater than a predetermined count value (for example, 4), the level is recognized as the reference level (S203, 204). Report to the module and the base station processor (S205). Then, the data call using the access parameter in the base station is controlled (S206).

If the overload increase is less than the reference load every cycle, the call control processor level is decreased for each cycle (S207), and the overload release counter is incremented each time the call control processor level becomes zero. (+1) (S208, S209). When the increased overload release counter reaches a target value (eg, 10) (S210), the call control processor level is recognized as Oxff, and the overload release is reported to the base station module (BSM) and the base station processor (S211).

That is, if the call restriction result level goes down by one level and the level 0 is repeated 10 times, it enters the overload release. Each call limit of overload level manages a separate database separately, and the call processing block refers to this database according to each level to limit the call. In the case of origination restriction, the base station processor (BSP) informs the load and level of the call control processor (CCP or BSP) so as to initially limit the origination.

In the base station processor, as shown in the flowchart of FIG. 8, the message of the access parameters is transmitted to the terminal using the access parameter allowance field value shown in FIG. 9 based on the allowance rate determined according to the overload control level class of the base station processor. Transmitting, causing the terminal to make outgoing data call control. Thereafter, the processor measures the load at a predetermined period (for example, 2 seconds) and compares the measured load with the base load (base_load) to determine the control level rising and falling.

Referring to FIG. 8, when the overload level and the overload occurrence of the overload state are reported to the base station module and the base station processor (S221), the allowance rate based on the overload control level is determined in the base station (S222). After determining the allowance value n as shown in FIG. 9 in the access parameter (S223), the control message is transmitted to the terminal using the control message (S224).

Then, the terminal controls the outgoing call by the allowance rate during the allowance test (S225), and the control processor repeats the procedure of measuring the load value every predetermined period (S226).

The overload control method using the connection parameter message in the high speed data communication system according to the present invention is a service that necessarily requires a session connection in the case of a data-only service such as a high speed data communication system, and controls an existing message. It can fundamentally solve the load increase caused by the continuous connection demand that can be caused by the overload scheme. In addition, since the data call origination control is performed from the terminal of the lowest level, it is an effective overload control algorithm that can increase the resource efficiency of the system. In addition, the overload method proposed in the present invention has the advantage that it is possible to control the data call differentially according to the overload level because the proposed overload control can be implemented.

Claims (8)

An overload control method in a high speed data communication system, Checking whether the occupancy of the processor measured for each control period for changing the control level according to the occupancy measurement period of the processor is equal to or greater than the reference load; Recognizing an initial overload level and reporting an overload occurrence to a processor and a module in the base station when the processor occupancy is equal to or greater than the reference load and continues for a time set as the processor occupancy target value; And limiting the originating call by transmitting an access parameter in the base station to the terminal. The method of claim 1, Decreasing the call control processor level by one level when the occupancy of the processor measured in each control period for changing the control level is less than a reference load; Confirming that the level of the reduced call control processor is at a minimum level; And overload releasing the count if the level is the minimum level and releasing the overload if the target count value corresponds to the target count value. The method according to claim 1 or 2, The control level is divided into 0 to 12 overload control classes for controlling outgoing data of a lower processor and 13 to 24 classes for requesting incoming call control to a higher processor for interworking between overload processors. Overload control method in system. The method of claim 3, The lower processor is a base station processor for outgoing call control, and the upper processor is a call control processor in a base station controller for incoming call control, and the reference load, reference level, and each overload control determined as initial overload according to the situation of the processor. An overload control method in a high-speed data communication system, characterized in that the allowable ratio set at a level can be arbitrarily changed. The method of claim 1, The overload control level corresponding to each of the control periods increases the overload control level when the measured load is greater than the initially set reference load in each cycle for measuring the occupancy of the processor, and decreases the overload control level when it is smaller than the reference load. An overload control method in a high speed data communication system characterized by maintaining a current level when it is within a reference load tolerance. The method of claim 5, Overload control in the high-speed data communication system, characterized in that the reference load that is the comparison target of the load measured in the control section includes the margin ratio for the target processor occupancy value so that the overload control level does not change frequently in each control section. Way. The method of claim 1, The base station processor and the call control processor have a database for measuring and storing the measured processor load, and update the overload detection flag database and the overload level database for each measurement period, and perform call control with reference thereto. An overload control method in a high speed data communication system. The method of claim 1, If the base station reports the occurrence of the overload, determining the transmission allowance rate by the overload control level in the base station processor, and then determining the allowance value in the access parameter; Transmitting an allowance field value in the determined access parameter to the terminal using a control message, and then causing the terminal to control the outgoing call based on the allowability in the allowance test. Control method.